MazF endoribonuclease promotes resolution of transcription-replication conflicts at ribosomal RNA genes in Escherichia coli.

ABSTRACT: Toxins from toxin-antitoxin (TA) systems, widely distributed genetic elements in prokaryotic genomes, are traditionally viewed as growth inhibitors. This study challenges this view by uncovering a growth-promoting function for MazF, the toxin component of the Escherichia coli MazF/MazE TA system. MazF is a sequence-specific endoribonuclease that cleaves single-stranded RNA, including ribosomal RNA (rRNA) precursors. While ectopic overexpression of MazF causes growth arrest, we show here that, when expressed at its native expression levels, it alleviates both co-directional and head-on transcription-replication conflicts at highly transcribed rRNA operons. By resolving these conflicts, MazF mitigates DNA damage, reduces cell mortality, and ultimately facilitates growth resumption. This func

SUBMITTER: Fleurier S 

PROVIDER: S-EPMC12541390 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature